Annex a iso11146 and iso11670 definitions – Gentec-EO Beamage-3.0 User Manual
Page 68
Beamage-3.0 User Manual Revision 6.0
67
ANNEX A ISO11146 AND ISO11670 DEFINITIONS
The beam centroid coordinates are given by:
̅( )
∫ ∫ ( )
∫ ∫ ( )
̅( )
∫ ∫ ( )
∫ ∫ ( )
The beam widths are defined as an
“extent of a power density distribution in a cross section of beam
based
on the centered second order moments of the power density distribution.”
The second order moments of power density distribution are given by:
( )
∫ ∫ ( )( ̅)
∫ ∫ ( )
( )
∫ ∫ ( )( ̅)
∫ ∫ ( )
( )
∫ ∫ ( )( ̅)( ̅)
∫ ∫ ( )
The beam widths are given by:
√ {(
)
[(
)
(
)
]
}
√ {(
)
[(
)
(
)
]
}
where:
|
|
The major axis is the width
’s maximum whereas the minor axis the width’s minimum.
The effective diameter of the beam is an
“extent of a circular power density having an ellipticity greater
than 0.87. […] If the ellipticity is larger than 0.87, the beam profile may be considered to be of circular
symmetry at that measuring location and the beam diameter can be obtained from:”